8-p-Coumaroylharpagide

Planta Med., 1997; 63(2): 171-176.

An Analytical Study and Anti-Inflammatory and Analgesic Effects of Harpagophytum procumbens and Harpagophytum zeyheri.[Reference: WebLink]

METHODS AND RESULTS:
The iridoids of Harpagophytum procumbens and Harpagophytum zeyheri were studied by CLHP. Harpagoside is the main iridoid for both drugs whereas 8-p-Coumaroylharpagide is a representative iridoid of Harpagophytum zeyheri only. The ratio harpagoside/8-p-Coumaroylharpagide can be used to distinguish chemically both species. For commercial dried aqueous extracts this ratio is intermediate because they are probably prepared from a mixture of H. procumbens and H. zeyheri drugs.
CONCLUSIONS:
The aqueous extracts of both drugs show similar analgesic and anti-inflammatory properties. Harpagophytum procumbens and Harpagophytum zeyheri should be accepted as sources for the drug Harpagophyti radix.

Natural Product Letters, 2005, 88(9):2532-2536.

A new iridoid glycoside from Scrophularia ningpoensis.[Reference: WebLink]

METHODS AND RESULTS:
A new iridoid glycoside, named 6′-O-cinnamoylharpagide (1), has been isolated from the roots of Scrophularia ningpoensis (Scrophulariaceae) together with nine known compounds, harpagide (2), harpagoside (3), 8-O-feruloylharpagide (4), 8-O-(p-coumaroyl)harpagide (8-p-Coumaroylharpagide, 5), 6-O-methylcatalpol (6), aucubin (7), buergerinin B (8), teuhircoside (9) and 6-O-cinnamoyl-D-glucopyranose (10).
CONCLUSIONS:
Compound 10 was obtained as an inseparable mixture of 6-O-cinnamoyl-α-D-glucopyranose and 6-O-cinnamoyl-β-D-glucopyranose at a ratio of 1 : 1, which is presumably formed by cleavage of compound 1. Their structures were elucidated on the basis of chemical and spectral analysis.